Dynamac Corporation c/o US Environmental Protection Agency, Cincinnati, OH 45268, USA.
Insect Mol Biol. 2010 Jun 1;19(3):381-9. doi: 10.1111/j.1365-2583.2010.00998.x. Epub 2010 Mar 10.
Crystal (Cry) proteins derived from Bacillus thuringiensis (Bt) have been widely used as a method of insect pest management for several decades. In recent years, a transgenic corn expressing the Cry3Bb1 toxin has been successfully used for protection against corn rootworm larvae (genus Diabrotica). The biological action of the Bt toxin in corn rootworms has not yet been clearly defined. Because development of resistance to Bt by corn rootworms will have huge economic and ecological costs, insight into larval response to Bt toxin is highly desirable. We identified 19 unique transcripts that are differentially expressed in D. virgifera virgifera larvae reared on corn transgenic for Cry3Bb1. Putative identities of these genes were consistent with impacts on metabolism and development. Analysis of highly modulated transcripts resulted in the characterization of genes coding for a member of a cysteine-rich secretory protein family and a glutamine-rich membrane protein. A third gene that was isolated encodes a nondescript 132 amino acid protein while a fourth highly modulated transcript could not be further characterized. Expression patterns of these four genes were strikingly different between susceptible and resistant western corn rootworm populations. These genes may provide useful targets for monitoring of Bt exposure patterns and resistance development in pest and non-target insect populations.
Cry 蛋白来源于苏云金芽孢杆菌（Bt），几十年来一直被广泛用作防治害虫的一种方法。近年来，一种表达 Cry3Bb1 毒素的转基因玉米成功地用于防治玉米根虫幼虫（Diabrotica 属）。Bt 毒素在玉米根虫中的生物作用尚未明确。由于玉米根虫对 Bt 的抗性发展将带来巨大的经济和生态成本，因此深入了解幼虫对 Bt 毒素的反应是非常可取的。我们鉴定了 19 个在转 Cry3Bb1 基因的玉米上饲养的 D. virgifera virgifera 幼虫中差异表达的独特转录本。这些基因的假定身份与代谢和发育的影响一致。对高度调控的转录本进行分析，鉴定出编码一个富含半胱氨酸的分泌蛋白家族成员和一个富含谷氨酰胺的膜蛋白的基因。第三个被分离的基因编码一个无特征的 132 个氨基酸蛋白，而第四个高度调控的转录本则无法进一步表征。这四个基因在敏感和抗性西部玉米根虫种群之间的表达模式差异显著。这些基因可能为监测害虫和非靶标昆虫种群中 Bt 的暴露模式和抗性发展提供有用的靶标。
